A PC card widely used for a personal computer or the like is standardized by PCMCIA and JEIDA, and the standardized PC card has outer dimensions of length 85.6 mm, width 54.0 mm and thickness 5.0 mm.
However, according to the decrease of the size of an apparatus such as a PDA, a portable telephone, a digital camera or the like, a smaller memory card has been required. For example, a memory card having outer dimensions of length 45.0 mm, width 42.8 mm and thickness 3.3 mm, for instance, or various memory cards having smaller sizes (e.g., postage stamp size) have been proposed, and such small memory cards are already in the market.
Under the above circumstance, adapters which enable the setting of such newly developed small memory cards into a slot for the widely used standardized PC card have been developed.
In these days, a memory card adapter of a beginning stage having a simple manual mechanism for ejecting the memory card has been replaced by a memory card adapter having an ejecting mechanism sophisticated for smoother ejection of the memory card.
Hereinafter the structure of a memory card adapter having the conventional ejecting mechanism is described.
On a circuit board held by a resinous frame, a memory IC (integrated circuit), a grounding coil spring, a connector and the like are mounted. The upper side and the lower side of the frame are respectively covered by metal plates. The grounding coil spring contacts with the metal plates. The connector of the memory card adapter contacts the signal-contact of the memory card when the memory card is set in the slot of the memory card adapter. An ejecting shaft for ejecting the memory card is disposed in the frame in such a manner as to be slidable along the inserting and ejecting direction of the memory card and to locate near the slot of the memory card adapter into which (i.e., the slot) the memory card is inserted. An arm having a bent portion at one end is disposed in such a manner that the center portion of the arm is rotatably supported by the resinous frame. The other end of the arm is connected to the ejecting shaft. The bent portion of the arm is formed in such a manner as to touch a portion of the memory card (which portion is located alongside the signal-contact of the memory card), and to hold the memory card inserted into the slot of the adapter.
In ejecting the memory card from the adapter having the above structure, the ejecting shaft is pushed with a finger along the inserting direction of the memory card. The pushing force applied to the ejecting shaft is conveyed to the bent portion of the arm, whereby the bent portion is moved along the ejecting direction touching the portion aside the signal-contact of the memory card, so that the memory card is ejected.
In some cases, a memory card has significant static electricity when the memory card is inserted into the slot of a memory card adapter. Therefore, it is essential to provide a grounding circuit for discharging the static electricity charged in the memory card before the signal-contact of the memory card contacts the connector of the memory card adapter. A device for discharging (i.e., grounding) static electricity charged in a memory card is proposed in Japanese Non-examined Patent Publication H7-28966, for instance.
However, in the above conventional structure, when a memory card is separated from the connector of the adapter by pushing the ejecting shaft of the adapter, the force for holding the memory card is removed. Thus, the memory card is forcibly ejected and slipped off from the slot of the adapter, which results in an inconvenience such as dropping the memory card on a floor giving a shock to the memory card or losing the memory card. Such inconvenience particularly is liable to occur in the case of a small and light memory card of postage stamp size. Also, in the conventional structure, a separate grounding device is needed, which results in the increase of the number of component parts and the increase of cost.